Arthur Sulzberger Jr., chairman and publisher of the New York Times. Photo: Reuters

The messy firing of Jill Abramson as executive editor at The New York Times is one more example of how the Times’ publisher, Arthur “Pinch” Sulzberger, fails the basics of Man­agement 101, and should be the one getting the ax.

Anyone in the business world who’s met Pinch will tell you: He’s not just a bad businessman; he’s one of the worst to run a major corporate enterprise, which the Times is, or at least used to be.

Plus, he’s the classic case of a guy born on third base who thinks he hit a triple: His great-grandfather bought the Times in the late 1800s, starting four generations of family ownership.

And Pinch lacks the self-awareness to get out of the way and let a real businessman run what appears to be a sinking ship.

Investors seem to agree: The paper’s stock dropped nearly 3 percent Tuesday, far worse than the rest of the market.

As a business reporter for 20-plus years, I’ve spent a lot of time in board rooms and newsrooms, so I’m under no illusions how tough it is to run a print operation in the Internet age.

But Sulzberger has made a bad situation even worse: He inherited one of the best brand names in corporate America (you may hate the Times’ politics, but it’s still a great paper), and has been running it down ever since.

Forget about the bath the Times took on The Boston Globe, selling it for barely half what it paid 20 years earlier.

Sulzberger’s “investments” to modernize in the digital era have been equally bone-headed, as the paper also lost big in buying and selling the search engine About.com.

And Pinch has transformed a once-stable news operation into a three-ring circus. He has gone through three editors and one chief executive in a little more than 10 years.

And CEO Janet Robinson was axed with a whopping $24 million golden parachute — not chump change for a big company, much less a financially struggling paper.

On the journalism side, Howell Raines was fired as editor amid one of the worst scandals in journalism history, when reporter Jayson Blair was finally caught making stuff up.

Sulzberger had embraced Raines despite (I’m told) his obvious shortcoming as a manager (widely hated in the newsroom), and Raines’ inevitable exit after the Blair fiasco was full of pomp and circumstance.

By contrast, I’m told Abramson was treated like a criminal, losing access to her e-mail and personal calendar nearly the moment she got the ax.

Keep in mind, when Sulzberger appointed her less than three years ago, he said she gave him “comfort and great confidence.”

She was a seasoned investigative reporter who’d worked for the Times since 1997, so presumably Pinch knew what he was dealing with when he gave her one of the most prestigious jobs in journalism. (Full disclosure: I had a cordial relationship with Abramson when we both worked at The Wall Street Journal.)

Then, last week, Sulzberger decided she had to go, apparently because he’d only just figured out that he doesn’t like a pushy woman running his personal playpen.

Yes, the Times is Sulzberger’s personal soap box.

For all its great reporting, it also mirrors the publisher’s doctrinaire liberalism, with full-on identity politics and outright cheerleading for lefty politicians.

Don’t get me wrong: Being autocratic is a trait that can be found in every successful chief executive I’ve encountered, not to mention some of the best editors I worked for.

Legendary GE exec Jack Welch, one of the most successful leaders of our time, sure didn’t run a democracy. But that’s different from a cult of personality surrounding a mercurial owner who seems clueless as to what he wants in a newsroom executive.

Abramson’s undoing reportedly began when she told Sulzberger she wanted to hire another deputy, someone with the same rank as Managing Editor (and Pinch toadie) Dean Baquet.

Her supposed crime: She didn’t smooth things over with Baquet first.

But how could she ever?

It should be Sulzberger’s job to make everyone happy. Instead, he chose the easiest (and dumbest, from a management standpoint) route and decided to fire Abramson — who by all accounts had a successful, scandal-free tenure as executive editor — to make nice with Baquet and install him in her place.

Sulzberger’s few defenders will note that the paper’s finances have stabilized in recent years. It has adapted as well as any of its peers to the digital age, and still produces high-quality journalism.

But, given the problems faced by all newspapers today, that’s like being the tallest midget in the room. The Times is still making relatively little money, circulation is falling and costs are rising.

Adapting to the way people increasingly prefer to get their news — over a computer or tablet — will take money and vision, something the guy running the Times circus clearly lacks.